Tool-holder



L. PRESBY.

TOOL HOLDER.

APPLICATION FILED MAR. 14. 19m.

1 3 36, 1 5 5 Patented Apr. 6, 1920.

UNITED STATES OFFICE.

LEROY Q. PRESBY, 0F MELRIOSE, MASSACHUSETTS, ASSIGNQR TO CLARENCE S. LUITWIELER, OF NEWTON, MASSACHUSETTS, AND FRANK W. MERRICK, OF

BOSTON, MASSACHUSETTS.

TOOL-HOLDER.

Application filed March 14,

To all whom it may concern:

Be it known that I, LEROY Q. PRESBY, a citizen of the United States, residing at Melrose, in the county of MiddleseX, State of Massachusetts, have invented a certain new and useful Improvement in Tool-Holders, of which the following is a specification, ref erence being had therein to the accompanying drawings.

The invention has relation to holders, more especially (though not exclusively) those used in the tool posts of lathes and other machine tools for the purpose of holding the tool-bits or cutters employed in the various processes of machining, boring, and the like.

The invention provides a new and improved holder comprising two clamping elements or jaws and so constituted as to hold with uniform firmness and stability toolbits of either square, or circular, or other crosssectional shapes of equal diameters in directions at right-angles to each other, and of diameters varying infinitely within the scope for which the particular size of holder may be constructed. Tool-bits usually are square in cross-section, made of stock manufactured in sizes differing by siXteenths of an inch. Round bits, of circular cross-section and of different diameters, are used for boring and other similar operations. Tool-holders now in use fit and handle efiiciently tools or bits of only one size, and are not adapted to receive, interchangeably, tools or bits of dif ferent shapes in crosssection. The invention effects a saving in that it renders unnecessary the number of tool-holders heretofore required to handle the difl'erent sizes and shapes of bits needed for different operations.

The invention consists, essentially, in a holder comprising two clamping elements having diagonally-opposite entrant angles, preferably right-angles, constituting seats adapted to receive corresponding portions of a tool or bit, means for applying pressure to close said clamping elements together, preferably in a direction at right-angles to opposite seat-faces which are parallel with each other, and means for guiding said clamping elements to move relative to each other in an oblique direction paralleling the Specification of Letters Patent.

Patented Apr. 6, 1920.

1919. Serial No. 282,604.

diagonal bisecting the opposite entrant ang es.

The invention includes also a special conr struction of tool-holder enabling the latter to be adjusted to function either as a righthand or a left-hand off-set holder, so that the tool may be employed as a right-hand or left-hand side tool and also so as to hold the tool or bit in a variety of angular positions, giving the latter manifold adaptability, so that one tool-holder is capable of being employed for a number of varieties of work for which separate forms of tool-holders have been required heretofore.

The drawings represent an illustrative embodiment of the features of the invention, which embodiment in itself constitutes one part of the invention.

In the drawings Figure l is a side elevation of the toolholder constituting the said illustrative embodiment, showing a tool arranged parallel with the shank, at the lefthand side of the latter.

Fig. 2 is a top view of the same.

Fig. 3 is an end view showing the position of the movable jaw in clamping a large tool of square cross-section, and Fig. 4 is a partly sectional end view showing the position said jaw assumes in grasping a small tool of similar shape in cross-section.

Fig. 5 is a top view of the holder with the jaws in a position at the right of the shank.

Figs. 6 and 7 illustrate other adjustments of the holder for various purposes.

Figs. 8 and 9 are end elevations showing the jaws holding cylindrical tool-shanks of different diameters.

The tool-holder shank 1 is constructed in the usual form for suitable use in the tool'- post of a lathe, and terminates in a horizontally disposed widened portion, through which is drilled a cylindrical hole to receive the assembling bolt 2, the said bolt having an enlargement or collar providing a shoulder which makes contact with the under surface of said widened portion around the hole therein that is occupied by the bolt.

Clamping elements or jaws of preferred form are shown at 5 and 8. The lower one, 5, rests upon the top of the said widened portion of the shank, and is surmounted by or jawr5.

the upper one, 8. These clamping elements or jaws have holes extending vertically therethrough, which are occupied by the stem of the assembling bolt 2. A nut 7 on the screw-threaded upper end of the bolt, above the upper jaw 8, keeps the parts in assembled relations and cooperates with the bolt in applying pressure to close the clamping elements or jaws 5, 8, together upon the tool or bit placed between them, so as to grasp and holdsaid tool or bit.

In the preferred form shown in the drawings, the lower clamping element or jaw 5 has upon its top a tool-seat constituted by a surface 5 extending at right-angles with the axis of bolt 2, and by a surface 5 extending parallel with said axis, the latter surfaces being provided by an inner shoulder of said element or j aw, these two surfaces 5*, 5 ac-' cordingly forming an entrant right-angle. The upper clamping element or jaw 8 has a tool-seat at its under side constituted by a surface 8 that is parallel with the opposing top surface 5 of lower clamping ele' ment or jaw 5, and by a surface 8 that is parallel with the surface 5 of the shoulder of the lower clamping element or jaw, said surface 8 being provided by an outer downturned shoulder or lip of said element or jaw, these two faces accordingly forming an entrant right-angle. The two entrant angles are, as will be perceived, located diagonally op osite each other.

'n the illustrated construction the upper clamping element or jaw. S is movable toward and from the lower clamping element As a means of guiding the upper element or jaw 8 to move relative to the lower element or jaw 5 in an oblique direction paralleling the obliquely-extending diagonal which bisects the opposite entrant angles of the two elements or jaws, the sald elements or jaws are formed with oblique surfaces 5, 8, contacting with and adapted to slide upon each other and each parallel with a plane bisecting the corresponding entrant angle. To permit the upper clamping element or jaw to move laterally with respect to the bolt 2-, the hole 8 through it is elongated as shown in Fig. 4i, and as indicated by dotted lines in Figs. 2 and 5, 6, and 7 In virtue of the provision for causing the relative movement to take place in an. oblique direction paralleling the diagonal which bisects the opposite entrant angles of the two clamping elements or jaws, the lateral component of the said movement and the vertical component thereof will always be equal to each other. Consequently,

so long as the portion of the tool or bit a' section as in Figs. 1 to 7, or round in crosswhichis square in cross-section in all conditions of adjustment. The parallelism of the contacting oblique surfaces 5, 8", with the diagonal which bisects said seats results in movement of the upper element or jaw horizontally at the same rate as it moves vertically, so that when the nut T is tightened the downward pressure exerted by the under surface 8 of element or jaw 8 upon thetop of the shank of the tool or bit is equalled by the lateral pressure exerted by theinner face 8 upon the outer side of said shank. Consequently the holder will grip the whole of the top and bottom faces of a square shank, and will makeflat contact with substantial portions of the other two sides, and also will hold a shank of circular cross-section securely through contact with its periphery on four lines at top, bottom, and opposite sides thereof.

The tool-seats are offset with relation to the bolt 2, so that they are adapted to hold the tool in a position non-radial of the bolt. Hence the tool or bit a may occupy, for instance, a position parallel with the shank 1, at one sideof the longitudinal axis of the latter as in some of theviews of the drawings. 'To provide for enabling thetoolholder to be adjusted so that it may function either as a right-hand olfset holder as in Fig. 5, or a left-hand offsetholder as in Fig. 2 and other views, enabling thereby the tool to be employed as either a righthand or a left-hand side-tool, and also provide for enabling the tool or bit to be given a variety of angular positions, non-radial with respect to the bolt, two of which are shown in Figs. 6 and '7, the clamping elements or jaws 5,8, aremade capable of be means of securely holding the tool-holder in each ofits adjusted positions, the top of the shank 1 is formed with a series of grooves 3, 3, radiating from the hole which receives the bolt 2, and the clamping element or jaw 5 is provided at its under side with one or more ribs 4: which enter the respective grooves. "When the nut 7 is tightened up so asto clamp the elements or jaws together upon the tool, the rib or ribs are kept thereby in the groove or grooves into which the same may have been entered. To hold bolt 2 from turning as the nut 7 is turned in elosingto'gether or opening up the clampingelements or jaws, it isprovided with a r longitudinally extending key 6, Fig. 4, which works in a groove formed in the shank 1 at one side of the hole occupied by the bolt.

While I have illustrated and described the preferred form of embodiment of the invention, I am aware that modifications may be made therein by any person skilled in the art without departing from the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to the particular forms shown, or to the details of construction thereof, but

What I do claim is,-

1. A holder comprising two clamping elements or jaws having diagonally-opposite entrant angles constituting seats adapted to receive corresponding portions of a tool, and means for applying pressure in a direction at right-angles to opposite seat-faces which are parallel with each other, and having means for guiding said clamping elements to move relative to each other in an oblique direction paralleling the diagonal which bisects the opposite entrant angles.

2. A holder comprising two clamping elements or jaws having diagonally-opposite entrant angles constituting seats adapted to receive corresponding portions of a tool, and means for applying pressure in a direction at right-angles to opposite seat-faces which are parallel with each other, also having means for guiding said clamping elements or jaws to move relative to each other in an oblique direction paralleling the diagonal which bisects the opposite entrant angles, and a supporting shank upon which said clamping elements or jaws are fixed with capacity for angular adjustability by said pressure applying means.

3. A holder comprising two clamping elements or jaws having diagonally opposite entrant angles adapted to receive corresponding portions of a tool, means for guiding said clamping elements or aws to move relative to each other in a direction paralleling the diagonal which bisects the said angles comprising contacting oblique surfaces paralleling the said diagonal, and means for drawing said clamping elements together, fixing them upon a shank, and holding them thereto in variable angular adjustment.

4. A tool-holder comprising two clamping elements or jaws having diagonally-opposite right-angled tool-seats, means for pressing said elements or jaws toward each other, and means for guiding them in an oblique direction paralleling the diagonal which bisects the angles of said seats.

5. A tool-holder comprising two clamping elements or jaws having diagonally-opposite entrant angles adapted to receive corresponding portions of a tool, contacting oblique guide-surfaces paralleling the diagonal which bisects said entrant angles, and means for applying pressure to force said clamping elements or jaws toward each other.

6. A tool-holder comprising two clamping elements or jaws having diagonally-opposite entrant angles adapted to receive corresponding portions of a tool, oblique guidesurfaces paralleling the diagonal which bisects the said entrant angles, a supporting shank, and a bolt by which said clamping elements or jaws are forced together and fixed in position upon said shank with variable angular adjustability.

7. A tool-holder comprising two clamping elements or jaws having diagonallyopposite entrant angles constituting seats adapted to receive corresponding portions of a tool, oblique guide-surfaces paralleling the diagonal which bisects the said entrant angles, a supporting shank, and a bolt by which said clamping elements or jaws are pressed together to hold the tool and are fixed in position upon said shank with capacity for adjustment to place said seats at either side of said shank.

8. A tool-holder comprising a shank, two clamping elements or jaws having seats adapted to receive a tool placed between said elements or jaws and to hold said tool in a position non-radial of the securing bolt, and said bolt, by which latter said clamping elements or jaws are pressed together to hold the tool and are fixed in position upon said shank with capacity for unison adjustment to place the seats in offset positions at either side of said bolt.

9. A tool-holder comprising a shank, a clamping bolt, and two grasping elements or j aws pressed together by means of said bolt and also secured thereby in position upon the said shank, said grasping elements or jaws having tool-seats which are adapted to hold the tool in a position non-radial of said bolt, and said grasping elements or jaws adjustable around the bolt to place the tool which is held in said. seats in varied angular positions.

In testimony whereof I affix my signature in presence of two witnesses.

LEROY Q. PRESBY. lVitnesses CrIAs. F. RANDALL, NATHAN B. DAY. 

